Abstract
Epilithic algae dominate cover on coral reefs globally, forming a critical ecological interface between the benthos and reef organisms. Yet, the drivers of epilithic algal composition, and how composition relates to the distribution of key taxa, remain unclear. We develop a novel metric, the Epilithic Algal Ratio, based on turf cover relative to total epilithic algae cover, and use this metric to assess cross-scale patterns. We reveal water quality and hydrodynamics as the key environmental drivers of the Epilithic Algal Ratio across the Great Barrier Reef (GBR), and reefs globally. On the GBR, the abundance of herbivorous fishes and juvenile corals were also related to the Epilithic Algal Ratio, suggesting that reefs with long-dense turfs support fewer herbivores and corals. Ultimately, epilithic algae represent the interface through which the effects of declining water quality, which impacts a third of reefs globally, can reverberate up through coral reefs, compromising their functioning.
Document Type
Journal Article
Volume
210
Funding Information
Australian Research Council / Ian Potter Foundation / Australian Museum's Lizard Island Research Station / AIMS / CRC Reef Research Centre / Australian Government's Marine and Tropical Science Research Facility / National Environmental Research Program / National Environmental Science Program
PubMed ID
39591677
School
Centre for Marine Ecosystems Research / School of Science
RAS ID
77149
Grant Number
ARC Numbers : FL190100062, FT200100949
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Publisher
Elsevier
Identifier
Alexandre C. Siqueira: https://orcid.org/0000-0001-7970-4024
Comments
Tebbett, S. B., Emslie, M. J., Jonker, M. J., Ling, S. D., Pratchett, M. S., Siqueira, A. C., ... & Bellwood, D. R. (2025). Epilithic algal composition and the functioning of Anthropocene coral reefs. Marine Pollution Bulletin, 210. https://doi.org/10.1016/j.marpolbul.2024.117322